// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2010 Hauke Heibel <hauke.heibel@gmail.com>
// Copyright (C) 2015 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#define TEST_ENABLE_TEMPORARY_TRACKING

#include "main.h"

template<int N, typename XprType>
void
use_n_times(const XprType& xpr)
{
	typename internal::nested_eval<XprType, N>::type mat(xpr);
	typename XprType::PlainObject res(mat.rows(), mat.cols());
	nb_temporaries--; // remove res
	res.setZero();
	for (int i = 0; i < N; ++i)
		res += mat;
}

template<int N, typename ReferenceType, typename XprType>
bool
verify_eval_type(const XprType&, const ReferenceType&)
{
	typedef typename internal::nested_eval<XprType, N>::type EvalType;
	return internal::is_same<typename internal::remove_all<EvalType>::type,
							 typename internal::remove_all<ReferenceType>::type>::value;
}

template<typename MatrixType>
void
run_nesting_ops_1(const MatrixType& _m)
{
	typename internal::nested_eval<MatrixType, 2>::type m(_m);

	// Make really sure that we are in debug mode!
	VERIFY_RAISES_ASSERT(eigen_assert(false));

	// The only intention of these tests is to ensure that this code does
	// not trigger any asserts or segmentation faults... more to come.
	VERIFY_IS_APPROX((m.transpose() * m).diagonal().sum(), (m.transpose() * m).diagonal().sum());
	VERIFY_IS_APPROX((m.transpose() * m).diagonal().array().abs().sum(),
					 (m.transpose() * m).diagonal().array().abs().sum());

	VERIFY_IS_APPROX((m.transpose() * m).array().abs().sum(), (m.transpose() * m).array().abs().sum());
}

template<typename MatrixType>
void
run_nesting_ops_2(const MatrixType& _m)
{
	typedef typename MatrixType::Scalar Scalar;
	Index rows = _m.rows();
	Index cols = _m.cols();
	MatrixType m1 = MatrixType::Random(rows, cols);
	Matrix<Scalar, MatrixType::RowsAtCompileTime, MatrixType::ColsAtCompileTime, ColMajor> m2;

	if ((MatrixType::SizeAtCompileTime == Dynamic)) {
		VERIFY_EVALUATION_COUNT(use_n_times<1>(m1 + m1 * m1), 1);
		VERIFY_EVALUATION_COUNT(use_n_times<10>(m1 + m1 * m1), 1);

		VERIFY_EVALUATION_COUNT(use_n_times<1>(m1.template triangularView<Lower>().solve(m1.col(0))), 1);
		VERIFY_EVALUATION_COUNT(use_n_times<10>(m1.template triangularView<Lower>().solve(m1.col(0))), 1);

		VERIFY_EVALUATION_COUNT(use_n_times<1>(Scalar(2) * m1.template triangularView<Lower>().solve(m1.col(0))),
								2); // FIXME could be one by applying the scaling in-place on the solve result
		VERIFY_EVALUATION_COUNT(use_n_times<1>(m1.col(0) + m1.template triangularView<Lower>().solve(m1.col(0))),
								2); // FIXME could be one by adding m1.col() inplace
		VERIFY_EVALUATION_COUNT(use_n_times<10>(m1.col(0) + m1.template triangularView<Lower>().solve(m1.col(0))), 2);
	}

	{
		VERIFY(verify_eval_type<10>(m1, m1));
		if (!NumTraits<Scalar>::IsComplex) {
			VERIFY(verify_eval_type<3>(2 * m1, 2 * m1));
			VERIFY(verify_eval_type<4>(2 * m1, m1));
		} else {
			VERIFY(verify_eval_type<2>(2 * m1, 2 * m1));
			VERIFY(verify_eval_type<3>(2 * m1, m1));
		}
		VERIFY(verify_eval_type<2>(m1 + m1, m1 + m1));
		VERIFY(verify_eval_type<3>(m1 + m1, m1));
		VERIFY(verify_eval_type<1>(m1 * m1.transpose(), m2));
		VERIFY(verify_eval_type<1>(m1 * (m1 + m1).transpose(), m2));
		VERIFY(verify_eval_type<2>(m1 * m1.transpose(), m2));
		VERIFY(verify_eval_type<1>(m1 + m1 * m1, m1));

		VERIFY(verify_eval_type<1>(m1.template triangularView<Lower>().solve(m1), m1));
		VERIFY(verify_eval_type<1>(m1 + m1.template triangularView<Lower>().solve(m1), m1));
	}
}

EIGEN_DECLARE_TEST(nesting_ops)
{
	CALL_SUBTEST_1(run_nesting_ops_1(MatrixXf::Random(25, 25)));
	CALL_SUBTEST_2(run_nesting_ops_1(MatrixXcd::Random(25, 25)));
	CALL_SUBTEST_3(run_nesting_ops_1(Matrix4f::Random()));
	CALL_SUBTEST_4(run_nesting_ops_1(Matrix2d::Random()));

	Index s = internal::random<int>(1, EIGEN_TEST_MAX_SIZE);
	CALL_SUBTEST_1(run_nesting_ops_2(MatrixXf(s, s)));
	CALL_SUBTEST_2(run_nesting_ops_2(MatrixXcd(s, s)));
	CALL_SUBTEST_3(run_nesting_ops_2(Matrix4f()));
	CALL_SUBTEST_4(run_nesting_ops_2(Matrix2d()));
	TEST_SET_BUT_UNUSED_VARIABLE(s)
}
